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Low purity kaolin clay is presently receiving attention as a promising aluminosilicate source that has the potential of extending the application of geopolymers because of its global abundance and low embodied energy, but its strength performance depends substantially on the calcination process, mineralogy of the clay, type and proportion of chemical activator etc.This work focuses on comparing the compressive strength of calcined clay geopolymer mortars activated by three forms of chemical activators.Three groups of geopolymer mortar mixes were prepared and tested, group one utilizes sodium hydroxide solution (NaOH) prepared by adding 68% water to the pellets 24 hrs prior to mixing, group two based on sodium silicate solution derived by adding 55.9% water to sodium metasilicate pentahydrate (Na2SiO3.5H2O)24 hrs prior to mixing, while the group three mixes were activated with industry produced Na2SiO3 solution that has 54.5% solid component.The results show that high compressive strength is achieved by developing calcined clay geopolymer mortar using high viscosity industry produced sodium silicate solution, while very low strength is achieved by utilizing sodium silicate containing chemically bounded water.The result further shows that the compressive strength of the geopolymer mortars are enhanced by sealed curing of the samples.

3D laser scanning and digital image correlation (DIC), two novel techniques capable of non-contact, full-field measurements of surface geometry and deformations respectively, have emerged and gained increasing applications in structural engineering research. The aim of the present study is to provide a state-of-the-art review and best-practice guidance on 3D laser scanning and DIC in the context of structural testing, and to introduce their main applications and advantages in physical experiments on metallic structures. For 3D laser scanning, the basic principles and general applications are firstly introduced. Laser scanning of a generic structural steel sample is subsequently described as a case study to demonstrate the workflow, with recommendations provided on the best practice. 3D laser scanning has been utilised in structural experiments for determining dimensional parameters, examining surface topography, characterising geometric imperfections of different forms and representing true geometry in finite element modelling, examples of which, along with corresponding data analysis methods, are provided and discussed. For DIC, following an initial review, the procedure for setting up a stereo DIC system in a stub column test is subsequently presented, where recommendations are provided on the setup, speckle pattern, execution and data processing. Example applications of DIC in various types of structural experiments, ranging from material tests to geometric imperfection measurements, structural element tests and structural system tests, are subsequently presented, and the advantages offered by DIC over conventional measurement methods are discussed. 3D laser scanning and DIC provide structural researchers with deeper insights into the geometric properties and behaviour of metallic structures in physical experiments, and the presented work will help to facilitate the broader and more effective use of these techniques among peer researchers. • A comprehensive, state-of-the-art introduction to 3D laser scanning technology and Digital Image Correlation (DIC) is presented. • The typical workflow and best practices for effective use of 3D laser scanning in structural testing are thoroughly discussed. • Key applications of 3D laser scanning in structural testing are explored, with practical examples provided. • Clear guidance is provided on the execution of DIC techniques in structural testing. • Notable applications of DIC in structural testing are presented and discussed.

In this work, the effects of calcination temperatures ranging from 600°C to 1,000°C on the changes in mineralogical phases and mechanical characteristics of calcined impure kaolinite clay blended cement mortars were investigated. The impact of calcining temperature on pozzolanic activity of impure kaolinite clay was evaluated using direct and indirect methods. The findings demonstrated that at 700°C, kaolinite changed from a crystalline to an amorphous metakaolin phase. Specific surface, water demand, and setting time of the blended cements decreased as calcining temperature increased. The compressive strengths of blended cement mortar containing low-grade clay calcined at 700°C, 800°C, and 900°C were found to be greater than that of 600°C and 1,000°C. Based on the results of pozzolanic reactivity evaluations and compressive strength development, the most effective calcining temperature was shown to be between 800°C and 900°C.

To the Editor: Hydrogen sulfide (H2S) has emerged as a new and important endogenous regulator of inflammation in recent years [1] and may also protect from emphysema induced by cigarette smoke exposure [2]. We have also recently shown that H2S can inhibit airway smooth muscle cell proliferation and inflammatory mediator release in vitro [3]. Serum levels of H2S positively correlate with the decline in lung function in chronic obstructive pulmonary disease (COPD) and were significantly lower in Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage III patients compared with those in GOLD I [4]. Existing therapies for COPD, such as corticosteroids or long-acting anticholinergic agents, may reduce the exacerbation rate but do not significantly slow disease progression. A previous study has shown that theophylline alone had no impact on serum H2S levels and is of limited value in the management of stable COPD [5]. Interestingly, sputum H2S measured in patients with asthma correlated with sputum neutrophil counts and the degree of airflow obstruction measured by forced expiratory volume in 1 s (FEV1) % predicted [6]. Moreover, combination therapy of an inhaled glucocorticoid with low-dose theophylline has been shown to attenuate airway inflammation in patients with COPD and reverse glucocorticoid resistance [7]. We therefore investigated whether the combination of inhaled corticosteroid and low-dose theophylline, as opposed to …

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To assess the cost-effectiveness of sirolimus-eluting stents (SESs) compared with bare metal stents (BMSs) as the default strategy in unselected patients treated in the Rapamycin Eluting Stent Evaluated At Rotterdam Cardiology Hospital (RESEARCH) Registry at 1 and 2-years following the procedure.A total of 508 consecutive patients with de novo lesions exclusively treated with SES were compared with 450 patients treated with BMS from the immediate preceding period. Resource use and costs of the index procedure, and clinical outcomes were prospectively recorded over a 2-year follow-up period. Follow-up costs were measured as unit costs per patient based on the incidence of clinically driven target vessel revascularization (TVR), to obtain cumulative costs at 1 and 2-years. Cost-effectiveness was measured as the incremental cost-effectiveness ratio (ICER) per TVR avoided. The use of SES cost euro 3,036 more per patient at the index procedure, driven by the price of SES. Follow-up costs after 1-year were euro 1,089 less with SES when compared with BMS, due to less TVR, resulting in a net excess cost of euro 1,968 per patient in the SES group, and reduced by a further euro 100 per patient in the second year. The incidence of death or myocardial infarction between groups was similar at 1 and 2 years. Rates of TVR in the SES and BMS groups were 3.7% vs. 10.4%, P<0.01 at 1 year, respectively; and 6.4% vs. 14.7%, P<0.001 at 2 years. The ICER per TVR avoided was euro 29,373 at 1 year, and euro 22,267 at 2 years.The use of SES, while significantly beneficial in reducing the need for repeat revascularization, was more expensive and not cost-effective in the RESEARCH registry at either 1 or 2-years when compared with BMS. On the basis of these results, in an unselected population with 1 year of follow-up, the unit price of SES would have to be euro 1,023 in order to be cost-neutral.

Limited data are currently available on the performance of everolimus eluting bioresorbable vascular scaffold (BVS) for treatment of complex coronary lesions representative of daily practice.This is a prospective, mono-center, single-arm study, reporting data after BVS implantation in patients presenting with stable, unstable angina, or non-ST segment elevation myocardial infarction caused by de novo stenotic lesions in native coronary arteries. No restrictions were applied to lesion complexity. Procedural results and 12-month clinical outcomes were reported.A total of 180 patients have been evaluated in the present study, with 249 treated coronary lesions. Device Success per lesion was 99.2%. A total of 119 calcified lesions were treated. Comparable results were observed among severe, moderate and noncalcified lesions in term of %diameter stenosis (%DS) (20.3 ± 10.5%, 17.8 ± 7.7%, 16.8 ± 8.6%; P = 0.112) and acute gain (1.36 ± 0.41 mm, 1.48 ± 0.44 mm, 1.56 ± 0.54 mm; P = 0.109). In bifurcations (54 lesions), side-branch ballooning after main vessel treatment was often performed (33.3%) with low rate of side-branch impairment (9.3%). A total of 29 cases with coronary total occlusions were treated. After BVS implantation %DS was not different from other lesion types (17.2 ± 9.4%, vs. 17.7 ± 8.6%; P = 0.780). At one year, all-cause mortality was reported in three cases. The rate of target lesion revascularization and target vessel revascularization was 3.3%. The rate of definite scaffold thrombosis was 2.6%.The implantation of the everolimus eluting bioresorbable vascular scaffold in an expanded range of coronary lesion types and clinical presentations was observed to be feasible with promising angiographic results and mid-term clinical outcomes. © 2016 Wiley Periodicals, Inc.

Aims Wall shear stress (WSS) estimated in models reconstructed from intravascular imaging and 3D-quantitative coronary angiography (QCA) data provides important prognostic information and enables the identification of high-risk lesions. However, these analyses are time-consuming and require expertise limiting WSS applications and adoption in clinical practice. Recently, a novel software has been developed for real-time computation of WSS and multidirectional WSS distribution. The aim of this study is to examine its inter-corelab reproducibility. Methods and results Sixty lesions (20 in coronary bifurcations) with a borderline negative fractional flow reserve were selected and processed using the CAAS Workstation WSS prototype (version 6.0 PIE MEDICAL) to estimate WSS and multi-directional WSS. Analysis was performed by two Core laboratories; the estimations of the two corelabs for the WSS in 3 mm segments across each reconstructed vessel were extracted and compared. To examine the concordance between inter-observer analysis of clinically relevant values, the scatterplot was divided into 4 quadrants with AS 61.3% and maximum WSS 8.24 Pa based on the previous publications and Cohen’s Kappa value was presented using these cut-off values. In total 700 segments (256 located in bifurcated vessels) were included in the present analysis. Average analysis time on the software was 219±45s in straight model and 291±61s in bifurcation model. A high intraclass correlation was noted for all the WSS metrics for the estimations of the two core labs irrespective of the presence (range: 0.90 – 0.92) or absence (range: 0.89 - 0.90) of a coronary bifurcation, while the ICC was good-moderate for the multidirectional WSS (range: 0.72-0.86). In addition, the bias between the WSS estimations was low and the limits of agreement were narrow in Bland-Altman analyses (Figure 1). When using the cut-off value of maximum WSS and % AS, a substantial agreement was noted between the two estimations of the two core labs; κ=0.77 for identifying maximum WSS &amp;gt;8.24Pa and κ=0.71 for identifying AS &amp;gt;61.3% (Figure 2). Conclusion The CAAS workstation enables reproducible 3D-QCA reconstruction and computation of WSS metrics. Further research is needed to explore its efficacy in predicting cardiovascular events.Figure 1Figure 2

Inhaled furosemide, a high ceiling diuretic, inhibits bronchoconstrictor responses to sodium metabisulfite (MBS) and other indirect challenges by unknown mechanisms. Furosemide acts by inhibition of Na+/Cl− transport in renal tubules and may exert similar effects on asthmatic airways. To evaluate this hypothesis we compared the effects of nebulized furosemide with those of bumetanide, another high ceiling diuretic that inhibits Na+/Cl− transport, on bronchial challenge with adenosine 5′-monophosphate (AMP) and MBS in 16 asthmatic subjects. We also studied the effects of furosemide on histamine-induced bronchoconstriction in seven of these subjects. Nine subjects inhaled furosemide (30 mg) or placebo (P) 30 min before challenge with nebulized AMP (0.39 to 400 mg/ml). Seven returned for similar study with histamine (0.125 to 32 mg/ml). In another study, seven subjects inhaled bumetanide (2 mg) or P 5 and 30 min before AMP and MBS (0.3 to 80 mg/ml) challenge. The provocative concentration causing a 20% fall in FEV1 (logPC20) was calculated by linear interpolation of log dose-response curves. Furosemide (F) significantly attenuated responses to AMP: mean ± SEM logPC20, 1.59 ± 0.24 (geometric mean PC20 [GM], 39.0 mg/ml) after F and 0.98 ± 0.29 (GM, 9.5 mg/ml) after P (p < 0.01), but it did not alter responsiveness to histamine: logPC20, 0.09 ± 0.17 (GM 1.2 mg/ml) after F and 0.09 ± 0.20 (GM, 1.2 mg/ml) after P. In contrast bumetanide (B) did not affect responses to AMP: at 5 min logPC20, 1.54 ± 0.19 (GM, 34.7 mg/ml) after B and 1.44 ± 0.15 (GM, 27.5 mg/ml) after P; at 30 min by logPC20, 1.33 ± 0.16 (GM, 21.4 mg/ml) after B, 1.17 ± 0.17 (GM, 14.8 mg/ml) after P, or to MBS: 0.83 ± 0.13 (GM, 6.8 mg/ml) after B and 0.80 ± 0.11 (GM, 6.3 mg/ml) after P. Thus, F inhibits airway responses to AMP by an action that is unlikely to involve airway smooth muscle as histamine-induced bronchoconstriction is unaffected. The degree of protection is comparable to that observed in our previous study with MBS challenge. Bumetanide, another loop diuretic, fails to inhibit either AMP or MBS bronchoconstriction, suggesting that the protective effect of furosemide is independent of Na+/Cl− inhibition.

Background Radioactive stents have been reported to reduce in-stent neointimal thickening. An unexpected increase in neointimal response was observed, however, at the stent-to-artery transitions, the so-called “edge effect.” To investigate the factors involved in this edge effect, we studied stents with 1 radioactive half and 1 regular nonradioactive half, thereby creating a midstent radioactive dose-falloff zone next to a nonradioactive stent-artery transition at one side and a radioactive stent-artery transition at the other side. Methods and Results Half-radioactive stents (n=20) and nonradioactive control stents (n=10) were implanted in the coronary arteries of Yucatan micropigs. Animals received aspirin and clopidogrel as antithrombotics. After 4 weeks, a significant midstent stenosis was observed by angiography in the half-radioactive stents. Two animals died suddenly because of coronary occlusion at this mid zone at 8 and 10 weeks. At 12-week follow-up angiography, intravascular ultrasound and histomorphometry showed a significant neointimal thickening at the midstent dose-falloff zone of the half-radioactive stents, but not at the stent-to-artery transitions at both extremities. Such a midstent response (mean angiographic late loss 1.0 mm) was not observed in the nonradioactive stents (mean loss 0.4 to 0.6 mm; P &lt; 0.01). Conclusions The edge effect of high-dose radioactive stents in porcine coronary arteries is associated with the combination of stent injury and radioactive dose falloff.